#include <stdio.h>
#include <assert.h>


int strlen(const char *str)
{
  int len;
  for(len = 0; str[len] != '\0'; len++);
  return len;
}

int main(int argc,char *argv[])
{
  char str[] = "";
  assert(argc == 2);
  printf("%d\n",strlen(argv[1]));

  assert(strlen("") == 0);
  assert(strlen(" ") == 1);
  assert(strlen(str) == 0);
  assert(strlen("123abc") == 6);

  return 0;
}
